Magnetic enhancement of ionization source for glow discharge mass spectrometry

Abstract

Magnetic field coupling to a gas discharge finds practical employment in several types of present-day low-pressure discharge assemblies, for example, in the duoplasmatron ion source and in commercial sputter atomization units serving to deposit coatings or films of sputtered material on selected substrates. To date, gas discharge ionization sources for glow discharge mass spectrometry (GDMS) (1), an analytical technique developed by researchers for inorganic solids analysis (2-5) and thin film process control (6), and which

Internal glow discharge-fourier transform ion cyclotron resonance mass spectrometry

“…From -100 to 60 em from the center of the magnet, the required voltage decreased. This decrease is consistent with results reported by Bentz and Harrison [23] that showed that as an external magnetic field was increased from 200 to 500 G the current for a constant voltage discharge increased. In our experiment with a constant current discharge, the voltage decreased with increasing magnetic field, as can be seen in Figure 5.…”

“…The effect of relatively low magnetic fields on glow discharges has been studied previously [22][23][24][25]. These fields, of no more than 800 G, were shown to increase ion currents in a GO-quadrupole mass spectrometer [22].…”

“…The suggested enhancement mechanism was that the magnetic field increases the electron path length, which thus increases the formation of both argon metastables and analyte ions . Other effects attributed to the presence of a magnetic field were higher sputter rates, higher currents at given voltages, and lower operating pressures [22,23).…”

An improved analytical performance of magnetically boosted radiofrequency glow discharge

“…Hence, a higher excitation/ionization efficiency is obtained. Previous reports on magnetically boosted glow discharges, for both optical emission spectroscopy and mass spectrometry, were mainly investigated in direct current glow discharges using hollow cathode, 19,20 coaxial cathode 21,22 or Grimm type 23 sources. Nevertheless, the benefits of combining an external magnetic field and a radiofrequency glow discharge have not yet been fully exploited for analytical purposes.…”

Optimization of an rf-powered magnetron glow discharge for the trace analysis of glasses and ceramics

“…In the analytical applications Penning discharge is used in optical emission spectrometry for the analysis of metals and alloys [7][8][9][10][11][12][13][14][15], only a few investigations have been reported in which magnetron glow discharge has been applied to the direct solid sampling for mass spectrometry [16][17][18][19]. Bentz and Harrison [16] investigated the effect of an axial magnetic field on ion signals from the coaxial cathode ion source. Sacks's group [9][10][11] studied the physical properties of a planar dc magnetron glow dis-…”